Device for use in making tennis strings



March 5, 1935.,

W. J. HAMBURGER DEVICE FOR USE IN MAKING TENNIS STRINGS I Filed July 18,1934 Invenror Wolrer J. Hamburger Patented Mar. 5, 1935 v UNITED, STATESV "1,99s,715 r H DEVICE FOR USE IN MAKING TENNIS 1 srnmos r y Walter J.Hamburger, Brookline, assignor V to H. Schindler & 00., Inc., Canton,Mass, a corporation of Massachusetts Application July 18,1934, SerialNo. 135565 2 claims.

This invention relates to the making of strings for'tennis rackets andthe like and particularly to the making of strings which are formedof ahas characteristics 'sufliciently different from those of the otherstrands of the cord so as to be easily identified from such strands. Themethod described in said application" consists in forming a web ofparallel strands laid in a colloidal binder, folding'said'web'longitudinally into the general shape of alcord,'laying alongone side of said folded web an'identifying strand which has the desiredcharacteristics, said identifying strand being laid under lessertensionthan the strands of the web, and then twisting the folded web and theidentifying strand together thereby to form the completed tennis string.

'Whenthe cord is twisted to form the completed'string the identifyingstrand, because of its lesser tension, will remain on the surface of thestring throughout the length thereof and will appear on the surface as amarker or identifying strand which spirals about the completed 'string-The present invention has relation-to a'novel device for folding theweb" and laying themarker strand alongside of'the folded web with thelesser tension above referred to. In order to give an understanding ofthe invention Ihave illustrated in the drawing a selected embodimentthereof which will now bedescribed after which the novel features willbe pointed out in the appended claims. I

In the drawing, Fig. 1 illustrates the web of strands from which thestring is made, said web showing the strands in parallel relation andunited by suitable glue or colloidal bindery Fig. 2 illustrates one formof the web-folding and strand-laying device; i

Fig. 3 illustrates a diiierent form of said device which is'designed tolay two identifying strands along the side of the folded web;

Fig. 4 is a section on the line 44, Fig. 2; Fig. 5 is a section on theline 5-5, Fig. 2; I Fig. 6 is a perspective view illustrating thestructure of the folded web as it comes from the web-folding andstrand-laying device shown in Fig. 2, said web having the identifyingstrand laid thereal'ong; c Fig. '7 is a fragmentary'view of a tennisstring made in accordance with this invention; Fig. 8 is an enlargedsection on the line 88, 5

v Fig. 9 is a view similar to Fig. 6 but showing the folded web with'itsidentifying strands as produced by the'structure shown in Fig. 3.

The tennis string or the'like which is produced 10 with this inventionis indicated generally at 1 in Figs. 7 and 8 and it comprises aplurality of strands or threads 2 of silk or any other suitable materialwhich are twisted together to form the completed string andare boundtogether by glue or some other colloidal binder 3, and also comprisesone or more identifying strands or marker strands indicated at 4, eachof which marker strands isflaid un -the surface of' the'completed'string 1 and spirals thereabout as shown in Fig. 7. L

.The marker strand has characteristics sufiiciently different from thoseof the strands 2 so that it canbe easily identified. This marker strand4 may differ from the other strands 2 in the matter of color or in thematter of material or in" the matter of'si zeorin any other Way by whichit can be readily identified. Preferably, however, I employ a markerstrand which has a characteristic color different from the color of thestrands 2.

'e number of the strands 2 making up the body of the string will varyaccording to the strengthfwhich fit isdesired that the finished stringshallhave and also 'inaccordance with the'characterof the material ofwhich the strands '2'. are made. Where the string is designed for atennis "string and is made of strands of silk it iscommon to use thirty,forty or fifty strands 40 in astring. c In making up a tennis string therequisite number of strands 2' are first arranged in parallel relationin the form of a web or ribbon 5 as shown in Fig. .1, and a suitablebinder is applied to the web 5 to bind the strands together inthis Webform. Such binder can beapplied bypassing the web 5,1 througha bath ofbinder material or by spraying the binding material on the web or in anyother suitable way. The binding mate- 5 rial which is used may be glueor any other suitable colloidal binder.

Where the binding material is applied by passing the web 5 of strands 2through a bath it will be preferable to feed. the web between squeezerolls after it issues from the bath to squeeze out the surplus bindingmaterial.

After the web 5 has been formed and before the binding material isentirely dried said web is folded longitudinally to form a generalcord-like structure, such as shown at 6 in Fig. 6 and at the same timean identifying strand 4 (or a plurality of identifying strands, ifdesired) is laid along the folded web on the exterior thereof asindicated in Fig. 6. The web is folded into the cord-like shape and theidentifying strand 4 is laid alongside of said folded web whilethebinding material is still in a tacky condition, and because of thisfact the identifying cord will adhere to the folded web and thefoldedwebwill retain its cord-like shape.

The identifying strand 4 is laid along the web under a lesser tensionthan that to which the strands 2 are subjected. The cord-like structurewith its attached identifying strand 4 is then twisted to form thecompleted string. The twisting of the cord-like structure twists thestrands 2 together and. because of the fact that the identifying strand4 has a less tension than the strands 2 said strands 4 will take aposition on the exterior of the finished string and will appear on thesurface of the string from one end to the other, said identifyingstrandv spiralling about the completed string in a uniform spiral asshown in Fig. 7. During the cord-twisting operation the strands 2 willbe drawn tightly together andmore or less of the binding material willbe forced to the surface of the completed cord. During this twistingoperation the identifying strand or marker strand 4 becomes partiallyembedded in the surface of the cord but yet remains exposed at thesurface and thus performs its function as a marker or identifyingstrand.

lhe presentinvention relates to a novel device for folding the web 5 andat the same time laying the marker strand along the side of the foldedweb. One form of the device herein. provided for this purpose isillustrated in Fig.v 2 and it comprises a trumpet-likefolding deviceindicated generally at 7 through which the web passes and by which it isfolded. This folding device 7 is preferably formed with a conicalreceiving portion 8 which is open at its larger 'end and a tubularportion 9 extending from the smaller end 'of the conical portion 8. Thedevice shown in Fig. 2 is also provided with a tubular marker-guidingelement 11 situated exterior to the tubular folding portion 9' and theconical entering portion 8, and one end of whichcommunicates with theinterior of theconical portion 8 near the open end thereof while theother end communicates with the bore of the tubular portion 9. Thismarker guiding element 11 is for the purpose of guiding the identifyingstrand or marker strand 4 into position and laying it alongside of thefolded web.

In using the device shown in Fig.2 the web 5 of parallel strands 2 isfed into theopen end of the trumpet member 7 and passes through thetubular portion 9. As the web passes from the small end of the conicalportion 8 into the tubular portion 9 it is folded to form a generalcord-like structure and as it emerges from the end of the tubular member9 it retains its cord-like structure. The web is fed through thisfolding trumpet while the binding material is still tacky and as aresult the edges of the web which are brought into contact by thefolding operation will adhere together sufficiently so that the foldedweb will retain its cord-like structure. I

As'the web 5 is being fed through the trumpet the identifying strand 4is fed through the guiding member 11 and is delivered to the tubularportion 9 adjacent the delivery end thereof.

This identifying strand 4 is delivered to the folding device underlesser tension than that to which the strands 2 are subjected and as itpasses into and through the guiding member 11 it will be delivered alongthe side of the folded web as shown in Fig. 6 and will adhere to saidweb because at this time the binding material is still in a tackycondition.

The article will be delivered from the trumpet member 7 in substantiallythe shape shown in Fig. 6 with the identifying strand 4 lying along andadhering tothe folded web but under somewhat, less tension than thestrands 2.

The cord-like structure is'then twisted to the desired extent to twistthe strands 2 together and because the identifying strand 4 is underalesser tension-said strand will assume a position, on the outside of thetwisted string where it will be visible throughout the length of thestring.

In Fig. 3 I have shown a construction similar to that shown in Fig.2except that it is provided with two strand-guiding elements 11, one oneach side. With this construction two identifying strands instead of onemay be laid alongside of the folded web as shown in Fig. 9. r

I claim: 1 1

1. A device for use in making tennis strings and the like from a web ofparallel strands laid in a colloidal binder, said device comprising atrumpet element having a hollow conical receiving portion into which theweb is fed and a tubular web-folding portion extending from the smallend of the conical portion and through which the web is fed and by whichit is folded into a cordlike structure, said trumpet element also havinga tubular strand-guiding member leading into and communicating with thetubular web-folding portion intermediate the ends thereof fordeliveringan identifying strand into said web-folding portion alongsideof and in contact with said cord-like structure while the latteristraveling through the web-folding portion.

, 2. A device for use in making tennis strings and the like from a webof parallel strands laid in a colloidal binder, said device comprising atrumpet element having a hollow conical receiving portion into which theweb is fed and a tubular web-folding portion extending from the smallend of the conical portion and through which the web is fed and by whichit is folded into a cord-like structure, said trumpet element alsohaving means to guide an identifying strand into said webfolding portionalongside of and in contact with said cord-like structure while thelatter is traveling through the web-folding portion.

WALTER J. HAMBURGER.

